1. No model for the Air Elemental exists in the final TFE game. However, the screenshot you've posted on the wiki is actually Kukulan, the first boss in The Second Encounter. That image is what he looks like without the red wind particle effects around him.

7. There are no Lava Rock Gun leftovers in TFE. I've searched the Player Weapon and projectile code for any traces of it, but I've found nothing. The model you claim is it is actually Ugh-Zan III's fireball gun he uses when you're fighting him.